Combining high switching frequency, exceptional power density, and a footprint small enough for embedded actuators, the platform enables next-generation robotic joints, end-effectors, and UAV propulsion systems while simplifying motor-control development.
The EPC91132 is a highly integrated three-phase BLDC motor drive reference design by EPC developed for compact robotic actuators, humanoid robot joints, end-effectors, and drone propulsion systems. Built around EPC’s EPC33110 monolithic GaN power module, the design demonstrates how gallium nitride (GaN) technology can significantly reduce inverter size while improving switching performance, efficiency, and power density. The reference platform addresses the growing demand for lightweight and space-constrained motor control systems where high dynamic response and thermal efficiency are critical design requirements.
At the core of the design is the EPC33110 three-phase GaN module, which integrates three half-bridge power stages, gate drivers, level shifters, and bootstrap circuitry within a compact 6 mm × 6.5 mm QFN package. This high level of integration reduces component count, simplifies PCB layout, minimizes parasitic inductance, and accelerates product development cycles. The module supports input voltages up to 80 V, operates from a single 5 V supply, and accepts both 3.3 V and 5 V logic-level control signals. The device exhibits a typical on-resistance of 11.7 mΩ, enabling low conduction losses and efficient high-frequency operation.
The EPC91132 reference board operates over a wide DC input range of 10 V to 60 V and integrates all major subsystems required for closed-loop motor control. These include an onboard microcontroller, regulated power supplies, phase-current sensing circuits, DC bus voltage monitoring, embedded overcurrent protection, and a magnetic encoder for rotor position and speed feedback. Real-time communication and system monitoring are supported through an RS-485 interface, while a dedicated programming connector allows straightforward firmware development and evaluation.
A key design feature is the board’s flexible breakout-ring architecture. With the outer ring removed, the inverter measures only 23 mm in diameter, making it suitable for integration directly into compact motor assemblies and drone propulsion platforms. Such miniaturisation enables distributed motor-drive architectures in robotics, where electronics can be embedded close to the actuator, reducing wiring complexity and improving control responsiveness.
The use of GaN technology enables switching frequencies above 100 kHz while maintaining low switching and conduction losses. Higher switching frequencies reduce passive component size, improve control bandwidth, enhance transient response, and contribute to overall system miniaturisation. Performance validation demonstrated continuous phase-current capability of 11 ARMS at 48 V with 100 kHz PWM operation. In drone motor evaluations, the design exhibited excellent thermal behaviour, with minimal temperature rise under propeller-induced airflow conditions. These characteristics make the EPC91132 a valuable reference platform for engineers developing next-generation robotic and UAV motor-drive systems requiring maximum power density, efficiency, and compactness.
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